RESUMO
Giardia duodenalis is divided into at least eight groups, named assemblages A to H. Assemblages A and B are the only ones able to infect humans and other mammals. The species status for these assemblies is a moot point, but has not gained general acceptance because sexual activity in Giardia is not completely understood. Heterozygosity in G. duodenalis can be detected through simultaneous identification of multiple loci in single cysts or trophozoites. In this paper, we describe a technique that enables simultaneous detection of fragments from four genes from single cysts of G. duodenalis recovered from stool samples. Each cyst from a fecal sample of human origin was separated, the DNA was extracted and amplified by means of multiplex PCR directed to four genes and the multiplex PCR product was further re-amplified using four single PCR (one for each gene). The following loci were detected: beta giardin (bg), GLORF-C4 (orfC4), triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh). This procedure should make it possible to investigate multiple genes from a single cyst of G. duodenalis assemblage A or B.
Assuntos
DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Giardia lamblia/genética , Fezes/parasitologia , Giardíase/parasitologia , Heterozigoto , Humanos , Micromanipulação , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da PolimeraseRESUMO
Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.